Improvement in steam-engine pistons



ned mes @sind @titi-rr. y

WILLl-AM G. SNOOK, OF CORNING, NEW YORK, ASSIGNOR TO HIM- SELF, A. H. GORTON, AND O. C. PATCHELL, OF SAME PLACE..

Letters Patent No. 90,884, :lated June `1, 1869.

IMPROVEMENT IN STEAM-ENGINE PISTONS.

The Schedule referred to in these Letters Patent and making part of the same.

To all whoml'it may concern.-

Be it known that I, WILLIAM G. Snoek, of Corn- 'ing,I county of Steuben, and .State of New York, have invented a new and useful Improvement in Pistons; andi do herebyvdeclare that the following is a full, clear, and exact description of the saine, reference being to the accompanying drawings, forrnnga part of this specification. v

This invention relates to pistons for steam-engines; and

It consists in'the' construction, combination, and arrangement of the parts of which it is composed, as will he more fully described hereinafter.

Figure 1 isa section online y y of iig. 2.

Figure 2 is asectional elevation on linexx of fig. l.

Figure 3 is a'detached view of a section or portion of one of the packing-rings.

Figure 4 is a side view, showing the periphery of the same. l

Corresponding letters inthe several figures refer to corresponding parts.

A A represent the body, or spider ofthe piston, it being formed inftwo sections, or parts, which meet each other at the line y y of tig. 2.

That portion of the piston represented by A, is made to t upon the piston-rod B, and to abut against a collar, d, upon said rod. That portion of said spider, or piston-head which is represented by A', is then to be slipped on to said rod, in which position the two are held,` by nut-s, upon the outer end of said rod, one of Y which acts as a jam-nut.

` The two divisions of the spider above referred to,

yare each furnished with a recess, a, in their peripheries, for the reception ofthe packing-rings L.

B is the piston-rod, which may be of any size and material adapted to the labor to be performed by it.

C represents a section, or piece of metal, which is to have a recess formed in its outer segmental surface, which recess is to be filled with Vwhat is known as Babbits metal, or, it may be, with any other suitably soft metal. rThis section, or slide is to be fitted into a re,-v cess, formed between the sections, or parts 0f the,spider, by cutting away a portion of each, equal to onehalf the thickness of the slide, or section C, and for a distance equal to the length of such slide, or section, This section, or slide, thus arranged, it will be seen, is capable of heilig slid out and in, in the recess formed within the sections of the spider, its oiice being to euable the engineer always to keep his piston centrally located within the cylinder, by providingthe means oi' raising the piston therein at any time, when, in consequence of its having worn away,it shall fall below the centre thereof.

D represents a cam, or eccentric, which is to be formed upon, or attached to the shaft F, and so arranged, with reference thereto, and to the slide, or section C, that as the fnllside of the cam is brought into contact with said slide, the same will be forced outward, and the piston raised within the cylinder.

E represents a' concentric wheel, which isto be sen sured to the shaft..y F, by the side oi' eccentric D, and is to have, upon its outer surface, scrrations, which constitute it a ratchet-wheel, for the reception of the end of the dog G.

F represents the shaft above alluded to, and to which the cam, or eccentric and ratchet-wheel, arc'to be secured. One end of this shaft may be stepped in a socket, formed in the interior surfaceof one section of the spider, while the other end is to pass through the opposite section, and have its bearings therein.

That portion of this shaft which projects beyond the surface of that section 'of the spider through which it passes, is to be squared,.or .otherwise prepared, for the reception of a wrench, or crank, with which to turn the same, so that, at any time that it may be desirable/ to raise the piston within the cylinder, it may be done, by removing the cylinder-head, and, through the medium of a wrench, or crank, turning this shaft; or, if preferred, au aperture may be formed in the cylinder-head, through which such crank, or wrench may be inserted, and thus the shaft be turned, without removing the cylinder-head, it being only necessary to provide such aperture with somesuitable cover, or stopper, to prevent-the esca-pe of steam from the cylinder.

Grepresents a dog,'which is to be pivoted to the interior surface of the piston, and so arranged, that when in position, its outer end will rest upon the wheel F.

H represents a spring, which is to be pivoted to the spiderand so arranged, as to bear upon the dog G, and thus keep its outer end in contact with 'the ratchet-wheel.

I I represent valves, which consist of a central disk, having a cylindrical projection upon each of its sides, the disks fitting into recesses in the sections A A of the spider, as clearly shown in iig. 2 ofthe drawings.

The cylindrical portions, or stems of these valves, are each of sufficient length to extend through the sections of the spider, and of sncient diameter t0 admit of having formed within them, recesses, which extend from their'outer ends inward, to nearly the point Where they join the disk.

Through the cylindrical portions of these valves, and at a distance about midway from the end thereof, to the point where they join the disks, apertures are to be formed, which apertures register with the passages b b, which allows ofthe passage of the steam from the cylinder to the recesses a in the sections of the spider. The arrangement of these valves, and their steam-passages, is to be such, that when the steam is admitted tothe cylinder, upon either side of the pistou, it will enter the' cavity in the ends of the valves, which are upon the side of the piston where such steam is admitted,and force such valves against their seats in the opposite section of such spiders, and, at the same time, cause the apertures in their stems to register with passages a in the spider, which will cause the sectional packing-ring in that section to be set out int-o steamtight contact with the cylinder, \vhile, at the same time, or during,r its passage in that direction, the aperture in the opposite end of such valve will be brought oppolsite the passage in the opposite section of the spider, thus permitting the steam to escape from under the rings in the last-named section of the spider.

K represents a spring, which may be a spiral one, and surround the stems of the valves, as shown in fig. 2; or'it may be a at or disk-spring, as shown in the same figure, and have a projecting rim upon its periphery, vvhich rixn may enter a slot, formed in the disk-portion ofthe valves. The former method of arranging these springs, is`tl1c one to which I give the preference; in either case they are to be so arranged, that when not acted upon by the pressure ot the steam, the valve will be held in a central position, and the disk will not hear upon either of its seats.

L represents segments, or sections of packing-rings, which are made to fit into the grooves, or recesses in the-.sections of the spider A A. These segments, or sections are constructed with lap-joints, so as to prevent the passage of steam from one sidethereof, to

' the other. They are also priovided with cavities, or

recesses in their peripheries, for the reception of soft What I claim, and desire to secure by Letters Patl 1. Thel roustruction of the hollow-stemmed valves I,- substantially as shown and described.

2. The combination and arrangement of the hollowstemmed' double-vented valves I, sections A A' of the spider, and the spring K,substantially as shown and described.

3. The combination of the eccentric D, the ratchetwheel F, and movable section of piston G, substantially as shown and described.

- 4. The arrangement of the springs K, with reference to the valves 1, substantially as shown and'described.

5. lhe arrangement of' the apertures inthe stems ot' valves I, with reference to the passages iulthe sections of the spider, leading to the recesses a beneath `the packing-rings, substantially as shown and described.

Witnesses:

J. H. WoLCoTT, A. S. KENDALL.

WILLIAM G. SNOOK. 

